SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4753ef835edc0d85c78625ea3f1dcec6054b1a7161961ec1507c56ac26a5eb80' 
  AND token = '6Kqiss0B7dGTj9zgdDbuEmRFhEqIMn3Qls/gNaFfyGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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