SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ff8b90f6e05856543c38d52fed98f8e025c98b8056e19466584ce0f8ee8fff' 
  AND token = '2uV948JJkdLoCSd7LxUFL8zNEvxahyck1xpIph1S6r0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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