SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2e960ef7af1d048c24d262a17061b53f5f07337e936160ddb415cb64cbdaf44' 
  AND token = 'FY0Bq5vM2Hh6wtp5mGbKDuitD5TJYoXTS8Bw/EwrKDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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