SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9952b750935a0400ab9a119d6c72bb13a00c288a46d23430dc46bdc456f601ef' 
  AND token = '40c9R1nGAcquVu3AEm+BY+RkhfrB4rE2i7PUE0imEL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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