SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44bd0bb77145e7a0760b121cfee990d3974ceb22aa3d88ad7d47215cf43b3a4b' 
  AND token = 'jL2buXk9mgPpOUrLhvuNuK8RZ9PxR6rlTv/jr1DzzUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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