SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9121454992448f38919138a76a5e8fc1d5bee07531ebc8fd2a9107c8d02a87ef' 
  AND token = 'Lwj1j0/PwR3vCTz73UNrkZB6ppwWfYjEA90t6/9rfLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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