SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '904608f2645551fe297ece5e2ce8c7d1240540d54374f46340e6555f30623b7e' 
  AND token = 'nbfHTz2U9Co/bqjD7+HH5My9LRllK2J+LlkT4pEddDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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