SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88122947dfa4c777bfe8f9982cbaf075b3e2c3ae9d329175c1071c3b99f6687b' 
  AND token = 'gmUsv+QjksUoSy/1poc+RZAJOuKP/88GPlBUwaIKcNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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