SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cdfcccc7608f09f60ba8b1232bf8cce3de3b2e823d0eb53d4f30123aa29c6ce' 
  AND token = 'ddIRwplg4Ux170BYH0sV+hniuxZFqflHRUlaGfVsMJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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