SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddf07bb767bad2c4bafa1599cecb32145713035bda18e171e2149d8f5d5e2455' 
  AND token = 'qTcdimafhE7otrVj/P7qs6nKtU4ENGma4jslcHvE2tc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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