SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8db20cbd4791f9a32acd7e27fc10d32383f8a555e66ead41d4082f39057093ec' 
  AND token = 'MukypbT5KU+74sTrhlGrmRWxuImpBqjYXPWZOUJ72S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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