SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd20a711894d2efcb856bcca737a4bdfb79d9a39333f7d097f811070d014810bf' 
  AND token = '+qgfn77XgzGA+FPNv64TbwtIuxEMCVfbaVF4tHUECXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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