SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ef582ba7f4c17e4559c6df6cea9eb836809091dfbbc668b50d8560b1b81226' 
  AND token = 'VwyPaN8bSlqULgx7dBXDpeYKpv6qdLdjdKFFDPxeX3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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