Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a12e6f3953f46f00e60569ab37b574777ff7aba9fe929996aafd6e6668ce9bbf' 
  AND token = 'GnTftaeI3AFBqhy/SYbzlqPOQXqGWa7jEbpkeLcCg+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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