SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57b17c216bcca718e9e1b630b0a5ad922e376aad3f2e1a7cc140414712c0bc7e' 
  AND token = 'cyWgyUn9fOuy97KuzNft0s31PTClxh6O5v+vBinXB7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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