SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e45f23c46ab1bc27e989ce225103f67026dd372f574cc89378af6c5d6063e6f' 
  AND token = '4LkytDQmGw9IieP13F9fNwBdQWYcWTVSSL4Tnx5bnhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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