SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dfc84bf5ef01441e0e04ff305461f370fd28540ab11278ce3fb64dce8282f31' 
  AND token = 'IgOR3ZjLJAT/f5dLazzU4XxsJsBYPVusGkXmloQ2+u4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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