SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39bdeb633e6b88719c649d6200144f788dd1c31d37e15dd646264c42f6b80025' 
  AND token = 'TtubIN4GypqDwS6/HSeib2bFpHSAd07UIywgiFoNLCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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