SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5cda3e0a0151d2cb0d6df1e23891662c441b4268fda2738392148a558cb7bb7' 
  AND token = 'yLQiZWzKp9/qq+YBvjJuaAZFivsWjU5Cjq7EkJvAMFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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