SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7fa66bd0d342f4424899f537698fecace014444800dd595b8811bab9c068f8c' 
  AND token = 'Tp3X1HdTCghCuLQFZa5ANJWbkqamyzF7MIY4+xv0RCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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