SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c5f514797d74c9b52ccb81070f4b71501818a68387ddf9c5329583afb9fb4e' 
  AND token = 'uB6MzyAcBdI/2BFg5eGnbf7at+8VqDt2LaHkgQwAWXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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