SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '841fbb5c04b976a3609d52a616e3ea5f36617de83f07186d0189fc2baed29cf5' 
  AND token = 'jnQUnZgaMCkmE3/smBRKJkHdzch51kwoah/vgi0wAuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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