SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d5211109ee28b63d6b0f4db46c246951e15f07f8d37e406276635c11b21fff5' 
  AND token = 'kB3Z/JaAb+wesK40LCoZGZ5hDzYRJyHQ1vOOn0A03qY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}