SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b1330d567d7e68303647791e0c5eb7a4d6af9eb06dda157fd4578101d49af62' 
  AND token = 'kuD1Re/HVijGMaffLvlX6MiNAK+OJbuz1OBupBCrFGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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