SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca20c4f15aea6bae64fecb91a59ad662feacba309c4f4795c084f79beb487ff9' 
  AND token = '4RPZZhL3h3Y09PtRNfCLc4f0Uh/ICUnUqdtJPsoAE3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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