SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49b9485a3fbae6728cdf986db50216ccb061015b2c85bc740a3ea01f812a3e28' 
  AND token = 'LysOVa24BPJ+dRuaW069fFNoocCurGgp1TFq9EcxdCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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