SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63ad4464e69bae58e26c50f73560cf15c808dbee0bbbc09571f3e3462ba94ff' 
  AND token = 'SOyRQKW46SthlTVcgpZRNmoNfoEJVZ8MMN0nHzcOMCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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