SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e817d04ff9abb851d45d83ce721dea939971d5befdc396a68988ec3329f6945' 
  AND token = 'piZLvRqXBRMBWXm7FDZsF11PFkLKHjEJx/nrKHsUzRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}