SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8c9432f8881f60c929536865e1c8b1642b3f90cadc1d5c4d53eb921fbe00c41' 
  AND token = 'vG7WjAZjaXAdzMgjrnTkiN0CF/O+F9ZaWPH81KSQmbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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