SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9171002acf2407dcd320f2ed269a19b21cdcdfae3d1994e5b71ebd48e971649b' 
  AND token = '2eHkur0xNreel0HF7RNUnL9ffKQQdQcJiLIq9srJBVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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