SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad9077d8237aee0912911a3d82c31ba98fd4b26dc0fd987ddaaf41fe336485a1' 
  AND token = '79UgYCATMXpdzW5Mq69jvXAGoPkkb2QrFPBpLbuGLQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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