SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '544edbb302e715600e835953530dfb05af3fb2c3fb89b56f96fcd7487f078ae6' 
  AND token = '05PgCuiWHuvyD5suMcJ/jA3QeqDFkvTI97+djkt8vZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00133

JSON explain

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