SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edac1d716b37f0f39c2258fab7f8e975fc989bbde78d0b20381c7e221290e3bc' 
  AND token = 'DJqgz/Rx1xz7vVV+CJJmVhGKUCUQDMfmOV8Ycu6QIeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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