SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e2f0e72262e8c484ce55d9e84a62cedfddd9be31093e6c3dac2a6fad91bbc8e' 
  AND token = 'brP5V04O/qoL7wPAcEmoiCZeQdJIAmA1uu03TmGNi4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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