SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de9563ced558573eadf2035a9dc4230692406181ffaf24550753fc86f69be007' 
  AND token = 'WHwTEwnDpHfWzv06+1/WtBiEKc1YYYeMqOQ95EcfXIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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