SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2ab140d01ebcee6e1c51e285916c87a6c7f7e957d6415ba1f96c1403806565b' 
  AND token = 'CtBX2VtDp1FKSlgEOz09gOfXTD8vK//E/6QKLmgL+qA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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