SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73118d865284606ed56b5dd94fa4aa5598069782cf29e74c2879e576534696ec' 
  AND token = 'btXrG3ssJMAaZPM5DpfBuodN/zkdsXIUymvwhxm2yv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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