SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a03ef6d212c4552416d89816cb54f6230b0822fc84bc9fb5b71febb309016bd7' 
  AND token = 'EBqUpuAZWkXckeCLOUlWw0os3FYJ4s44Lds8z5s51zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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