SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2118fd0e01b285dc624f201a0fcd9a890204252abf6c369c794d08b5f7e84331' 
  AND token = 'r24uv7gVdhbMS/yCs/K/iwW+P8Z77hvCWnEYXVnX740=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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