SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81d46cfc331d904e91d06ffe584f493051280516cae1738e4bb943e0a855c08c' 
  AND token = 'IJIENHrewTOrWOYISAQsX49LoIfoL07S5vzmXekPECo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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