SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b3895d2e08ea538d8992ee8b5000e9003aff05bb4746dcaf513fa611b65cd92' 
  AND token = 'V4NdqvItUG3KKryvqtZoL/gG98dsEkTs5+KbEKyJiZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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