SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0b5db30fc9165a42a248f77a3853f3c5e5ab48fdb9f3ef19ea31490f08392bc8' 
  AND token = 'CnoNPYcUte5byPD2hhw9mF8+MukNlv3xhU8jaepP7E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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