SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd327c778b55138e08d769cbb1f693adeaa384c7a18ed3b68b069fa5bdba1146c' 
  AND token = 'yYX8SCe50vPiT2KwmrLEg4WwQv9uEUa2CWj4HVmZtiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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