SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f8689f572b0b909f6779cfb23d054d1ba31b1788ffd27cb9e219d6742924786' 
  AND token = '9PCK6dPcDPZ+PnwYCio1qdROFPRMcVkePggNARcLzsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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