SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09e4e13f1fd24f4da1880be1703b321866e6be2fad7ddfb498abeea8fd99e47' 
  AND token = 'jz/3UBmD4BJSLTDH8YKP+/v+pijQzUN9yjgt0BQFMZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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