SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c30c947b79d7490fba8bce7063f99277386291b9c5626b870302e80c3cb2721a' 
  AND token = 'zuBAgi8nMLJHUSUo1852FDud+QctaohdVGjBw0AaBfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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