SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fef47e347aa1e259bdb8f7fb46f34d597e0a1d6f7803e743757cdf735c62fd2' 
  AND token = 'VeH7AkyaRyvC1HI9erFIeEazncRsZ59sjqipF0LO1GI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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