SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '034836de0d50cc32445aa7f01e6d5ece9cad521233682c4bb7affd83a090c302' 
  AND token = 'CMClLkgcM0wJiouXDsV9rjXtO+r+gRPlVA5FNk2r8ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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