SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '25daede206c2674047d7154e193290e92dcbe37669acfff95335fca17855bbd3' 
  AND token = 'MdZiWQYlYStqbu5cLfC5EaVa6fidfTNOzt2r5Jc3IcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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