SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71bc063ffbc888f9543f977624fb6539d323697c52fdf87623ed8e610530f65d' 
  AND token = 'MZFHyz1VvppnpaU8a5qrwhPtkIjw3Qzgi3MAzHW1Ixk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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