SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6185abfe267de597e0f9ee3958273e0628a45742e2f8080ab7017236c9b82aa9' 
  AND token = 'K8UQMpMRrJT3XOhcPvKCgAVRZ0cjhzUlvf4Px7TbsAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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