SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b3ae6bece913ed9db0a7f5cbd63c13495500d1805aa3b17e3dd731c1eba8c6f' 
  AND token = 'WIkFzn7DWzkhUaYR2AMRHLbMHWCDl2tcbrsVtJQdtUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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