SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b93553044511adc8db04a7d14133e1581044ae95a6082ece4cbc020319f8dd5' 
  AND token = 'RdGkRCgIIb2dTzL1OMnycm6ikbpcgVx2cF9U/IBMi74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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