SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed888fd254baac13bcb95203799f7fbcbb8165ffcf6668c49214d14c7c83c3e9' 
  AND token = 'RUfj/tEDREFD6b1AagTnTm7nwUTcpmnGsjqtF4PC7VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}