SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a94b14cf0dcbc22542b41935ae335f6ce08bc794c1b4fc8433db9c3d08b3f52c' 
  AND token = 'ZZa3E1q5FYviWHaDq5uH5B5Gojs9F94UlSVwjQHP0co=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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