SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31537d54928e2e0671f6c4f604855824754ed292f94368018232e15c0bcb39a2' 
  AND token = 'MpAxJ0g6I/a3qu/RX5zXYnommDMYJpm9QhEUYuNvcrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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